Abstract
Immune checkpoint inhibitors have revolutionized cancer treatment by targeting the cytotoxic T lymphocyte antigen-4 and programmed death-1/ligand-1. Although immune checkpoint inhibitors show promising therapeutic efficacy, they often cause immune-related adverse events. Immune-related adverse events differ from the side effects of conventional chemotherapy and require vigilant monitoring. These events predominantly affect organs, such as the colon, liver, lungs, pituitary gland, thyroid and skin, with rare cases affecting the heart, nervous system and other tissues. As immune-related adverse events result from immune activation, indicating the reinvigoration of exhausted immune cells that attack both tumors and normal tissues, it is theoretically possible that immune-related adverse events may signal a better response to immune checkpoint inhibitor therapy. Recent retrospective studies have explored the link between immune-related adverse event development and clinical efficacy; however, the predictive value of immune-related adverse events in the immune checkpoint inhibitor response remains unclear. Additionally, studies have focused on immune-related adverse events, timing of onset and immunosuppressive treatments. This review focuses on pivotal studies of the association between immune-related adverse events and outcomes in patients treated with immune checkpoint inhibitors.